fix: copy events and search results in InMemoryMemoryService

Merge #7566

InMemoryMemoryService now stores deep copies of ingested events and
search_memory returns a deep copy of each event's content, so editing an
ingested event or a returned MemoryEntry no longer changes stored memory
or the source session.

Fixes #7565

PiperOrigin-RevId: 1003200266

Author: hackermengzhi

src/google/adk/memory/in_memory_memory_service.py

@@ -103,7 +103,7 @@ async def add_session_to_memory(self, session: Session) -> None:
       deleted_ids = self._deleted_memory_ids.get(user_key, set())
       self._session_events[user_key] = self._session_events.get(user_key, {})
       self._session_events[user_key][session.id] = [
-          event
+          event.model_copy(deep=True)
           for event in session.events
           if event.content
           and event.content.parts
@@ -136,7 +136,7 @@ async def add_events_to_memory(
       existing_ids = {event.id for event in existing_events}
       for event in events_to_add:
         if event.id not in existing_ids and event.id not in deleted_ids:
-          existing_events.append(event)
+          existing_events.append(event.model_copy(deep=True))
           existing_ids.add(event.id)
       self._session_events[user_key][scoped_session_id] = existing_events
 
@@ -182,7 +182,7 @@ async def search_memory(
               matched_words,
               MemoryEntry(
                   id=event.id,
-                  content=event.content,
+                  content=event.content.model_copy(deep=True),
                   author=event.author,
                   timestamp=_utils.format_timestamp(event.timestamp),
               ),

tests/unittests/memory/test_in_memory_memory_service.py

@@ -941,3 +941,73 @@ def reader():
   assert (
       not errors
   ), f'search_memory raced with concurrent deletes: {errors[0]!r}'
+
+
+@pytest.mark.parametrize('ingest_session', [True, False])
+async def test_ingested_events_are_detached_from_the_caller(
+    ingest_session: bool,
+) -> None:
+  """Changing an ingested event must not rewrite stored memory."""
+  service = InMemoryMemoryService()
+  session = MOCK_SESSION_1.model_copy(deep=True)
+  event = session.events[0]
+  original_content = event.content.model_copy(deep=True)
+  if ingest_session:
+    await service.add_session_to_memory(session)
+  else:
+    await service.add_events_to_memory(
+        app_name=session.app_name,
+        user_id=session.user_id,
+        session_id=session.id,
+        events=[event],
+    )
+
+  event.id = 'changed-id'
+  event.content.parts[0].text = 'replaced by the caller'
+  result = await service.search_memory(
+      app_name=session.app_name, user_id=session.user_id, query='toolkit'
+  )
+
+  assert len(result.memories) == 1
+  assert result.memories[0].id == 'event-1a'
+  assert result.memories[0].content == original_content
+
+
+@pytest.mark.parametrize('ingest_session', [True, False])
+async def test_search_results_are_detached_from_stored_memory(
+    ingest_session: bool,
+) -> None:
+  """Editing returned content must not affect memory or the source session."""
+  service = InMemoryMemoryService()
+  session = MOCK_SESSION_1.model_copy(deep=True)
+  event = session.events[0]
+  event.content.parts.append(
+      types.Part.from_function_call(
+          name='lookup', args={'options': {'color': 'blue'}}
+      )
+  )
+  original_content = event.content.model_copy(deep=True)
+  if ingest_session:
+    await service.add_session_to_memory(session)
+  else:
+    await service.add_events_to_memory(
+        app_name=session.app_name,
+        user_id=session.user_id,
+        session_id=session.id,
+        events=[event],
+    )
+  result = await service.search_memory(
+      app_name=session.app_name, user_id=session.user_id, query='toolkit'
+  )
+
+  returned_content = result.memories[0].content
+  returned_content.parts[0].text = 'replaced by the caller'
+  returned_content.parts[1].function_call.args['options']['color'] = 'red'
+  returned_content.parts.append(types.Part(text='extra content'))
+  repeated = await service.search_memory(
+      app_name=session.app_name, user_id=session.user_id, query='toolkit'
+  )
+
+  assert len(repeated.memories) == 1
+  assert repeated.memories[0].content == original_content
+  assert event.content == original_content